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smart-group-server-xl/G2ProtocolHandler.cpp

171 lines
4.0 KiB

/*
* Copyright (C) 2010,2011,2013 by Jonathan Naylor G4KLX
* Copyright (c) 2017-2018 by Thomas A. Early N7TAE
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <string>
#include "G2ProtocolHandler.h"
#include "Utils.h"
// #define DUMP_TX
const unsigned int BUFFER_LENGTH = 255U;
CG2ProtocolHandler::CG2ProtocolHandler(unsigned int port, const std::string& addr) :
m_socket(addr, port),
m_type(GT_NONE),
m_buffer(NULL),
m_length(0U),
m_address(),
m_port(0U)
{
m_buffer = new unsigned char[BUFFER_LENGTH];
}
CG2ProtocolHandler::~CG2ProtocolHandler()
{
delete[] m_buffer;
portmap.clear();
}
bool CG2ProtocolHandler::open()
{
return m_socket.open();
}
bool CG2ProtocolHandler::writeHeader(const CHeaderData& header)
{
unsigned char buffer[60U];
unsigned int length = header.getG2Data(buffer, 60U, true);
#if defined(DUMP_TX)
CUtils::dump("Sending Header", buffer, length);
#endif
in_addr addr = header.getYourAddress();
auto found = portmap.find(addr.s_addr);
unsigned int port = (portmap.end()==found) ? header.getYourPort() : found->second;
for (unsigned int i = 0U; i < 5U; i++) {
bool res = m_socket.write(buffer, length, addr, port);
if (!res)
return false;
}
return true;
}
bool CG2ProtocolHandler::writeAMBE(const CAMBEData& data)
{
unsigned char buffer[40U];
unsigned int length = data.getG2Data(buffer, 40U);
#if defined(DUMP_TX)
CUtils::dump("Sending Data", buffer, length);
#endif
in_addr addr = data.getYourAddress();
auto found = portmap.find(addr.s_addr);
unsigned int port = (portmap.end()==found) ? data.getYourPort() : found->second;
return m_socket.write(buffer, length, addr, port);
}
G2_TYPE CG2ProtocolHandler::read()
{
bool res = true;
// Loop until we have no more data from the socket or we have data for the higher layers
while (res)
res = readPackets();
return m_type;
}
bool CG2ProtocolHandler::readPackets()
{
m_type = GT_NONE;
// No more data?
int length = m_socket.read(m_buffer, BUFFER_LENGTH, m_address, m_port);
if (length <= 0)
return false;
m_length = length;
// save the incoming port (this is to enable mobile hotspots)
if (portmap.end() == portmap.find(m_address.s_addr)) {
printf("new address %s on port %u\n", inet_ntoa(m_address), m_port);
portmap[m_address.s_addr] = m_port;
} else {
if (portmap[m_address.s_addr] != m_port) {
printf("new port for %s is %u, was %u\n", inet_ntoa(m_address), m_port, portmap[m_address.s_addr]);
portmap[m_address.s_addr] = m_port;
}
}
if (m_buffer[0] != 'D' || m_buffer[1] != 'S' || m_buffer[2] != 'V' || m_buffer[3] != 'T') {
return true;
} else {
// Header or data packet type?
if ((m_buffer[14] & 0x80) == 0x80)
m_type = GT_HEADER;
else
m_type = GT_AMBE;
return false;
}
}
CHeaderData* CG2ProtocolHandler::readHeader()
{
if (m_type != GT_HEADER)
return NULL;
CHeaderData* header = new CHeaderData;
// G2 checksums are unreliable
bool res = header->setG2Data(m_buffer, m_length, false, m_address, m_port);
if (!res) {
delete header;
return NULL;
}
return header;
}
CAMBEData* CG2ProtocolHandler::readAMBE()
{
if (m_type != GT_AMBE)
return NULL;
CAMBEData* data = new CAMBEData;
bool res = data->setG2Data(m_buffer, m_length, m_address, m_port);
if (!res) {
delete data;
return NULL;
}
return data;
}
void CG2ProtocolHandler::close()
{
m_socket.close();
}

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